Cable duct installation tool



July 11, 1961 w. H. BINGHAM 2,991,974

CABLE DUCT INSTALLATION TooL Filed Aug. 18, 1960 `I f J 9 (17 es 15 u /h\\ vw WML/AM H B/N/L/AM INVENTOR.

ATTORNEY Patented July 11, 1961 2,991,974 CABLE DUCT INSTALLATION TOOL William H. Bingham, 3508 Boyce lAve., Fort Worth 15, Tex. Filed Aug. 18, 1960, Ser. No. 50,347 1 Claim. (Cl. 254-29) This invention relates to a cable duct installation tool, 4and it concerns more particularly a hydraulically operable device for use in driving sectional tubular metal conduits under paved surfaces, such `as airport runways, to provide ducts below the pavement, and extending across it from one side to the other, adapted Vto receive electrical cables.

Airport runways maybe of the order of about 150 feet wide, for example, and it is not practical to break the paved surface of a runway, while the runway is in use, 'for the purpose of installing ducts below the pavement, and traversing the runway, for insertion of electrical cables.

An object of this invention is to provide practical, efficient means including a hydraulic ram ladapted to drive a sectional tubular metal conduit, the length of which may be progressively increased by connecting additional sections thereto yas the operation proceeds, under a paved surface from one side thereof, for the purpose described.

The invention will be readily understood by referring to the following description and the accompanying drawing, in which:

FIG. 1 is a side elevational view, partly broken away to show details of construction, of a cable duct installation tool embodying the invention;

FIG. 2 is -a top plan view, partly broken away;

FIG. 3 is a sectional elevational view taken on the line 3 3 of FIG. 2;

FIG. 4 is `a fragmentary sectional elevational View, on an enlarged scale, taken on the line 4 4 of FIG. 2; and

FIG. 5 is a sectional elevational view taken on lthe line 5-5 of FIG. 4.

Referring to the drawing, the numeral 1 designates generally a hydraulic ram having a cylinder 2 and a plunger 3. A pair of flexible conduits 4 are connected to opposite ends of the cylinder 2 whereby the cylinder 2 is adapted to be operatively connected to a source of iluid pressure, such as a portable pump and engine unit (not shown).

The plunger 3 of the hydraulic ram 1 is movable reciprocally and continuously relative to the cylinder 2 in response to the action of fluid pressure applied to opposite ends of the cylinder 2 thru the exible conduits 4.

The hydraulic ram 1 is mounted on a wheeled carriage as hereinafter described, indicated generally by the numeral 5.

The carriage 5 has an elongated frame including a horizontally disposed, substantially rectangular base plate 6, an end plate 7 which is positioned adjacent one end of the base plate 6 and extends upwardly therefrom, and a pair of side rails 8, right angular in transverse section, which are arranged along opposite sides of the base plate 6 and are connected thereto by end portions 9, which are inclined in the vertical plane, positioned adjacent the end of the base plate 6 opposite the end plate 7.

The base plate 6, the end plate 7, and the side rails 8 together form a cradle supporting the hydraulic ram 1, the cylinder 2 of which is arranged on its side between the side rails 8 'with one of its ends abutting Ithe end plate 7. The plunger 3 extends outwardly beyond the end of Ithe carriage S opposite the end plate 7.

The frame of the carriage 5 is supported on a pair of axles 10 which are positioned below the Ibase plate 6, adjacent opposite ends thereof. The axles 10' are arranged transversely of the base plate 6, and extend outwardly 'beyond opposite sides thereof. Two pairs of Wheels 11 are journaled on the extended end portions 0f the axles 10.

An integral track unit as hereinafter described, indicated generally by the numeral 12, is adapted to be arranged in a trench extending laterally outwardly from one side of a paved surface, such as an airport runway, whereby the track unit 12 is positioned at a lower elevation than the pavement, perpendicular to the adjacent side thereof.

The track unit 12 includes a pair of parallel, spaced apart elongated rail elements 13, channel shaped in transverse section, having their side flanges arranged in opposed relation to each other. The wheels 11 of the carriage l5 are engageable between the side flanges of the respective elongated rail elements 13, which form ya track therefor whereby the carriage 5 is supported for longitudinal movement relative to the track unit 12.

The track unit 12 further includes a ibase structure underlying the elongated rail elements 13 and providing a support therefor, consisting of a pair of side rails 14, right angular in transverse section, arranged parallel to and below the elongated rail elements 13, anda plurality of uniformly spaced cross bars 15 whereby the side rails 14 are connected intermediate their ends.

An upstanding end plate 16 is connected to one end of the track unit f12 for abutment against the outer end of a trench as above described to prevent longitudinal displacement of the track unit 12 in an outward direction relative to the trench.

A pawl 17 is pivotally connected to a pair of lugs 1-8 extending outwardly from the side of the end plate 7 opposite the cylinder 2. A pair of pawls 19 are pivotally connected, respectively, to two pairs of lugs 20 extending upwardly from the inclined end portions 9 of the side rails 8, adjacent the opposite end of the carriage 5.

The pawls 17 and 19, respectively, `in their operative positions are selectively engageable with the cross bars 15 of the track unit 12 to prevent longitudinal movement of lthe carriage 5 relative to the track unit 12 in one direction 'while permitting movement of the carriage 5 in the opposite direction in response to the action of the hydraulic ram 1.

The pawls '17 and 19, which are employed alternatively to control the direction of movement of the carriage 5 relative to the track unit 12, are adapted to be folded upwardly over the corresponding ends of the cylinder 2 in their inoperative positions.

Two pairs of handles 21 which are connected to opposite sides of the cylinder 2, are removably connected to the side rails 8, by bolts 22 having nuts 23 applied thereto, whereby the hydraulic ram 1 is secured to the carriage 5.

The end of the carriage 5 which carries the pawl 17 is positioned nearest the outer end of the track unit 12, facing the end plate 16, rearwardly of the carriage relative to its movement in a forward direction as hereinafter described.

A tubular metal conduit 24, which initially comprises a single section, and to which other sections advantageously may be connected as the operation proceeds, to thereby increase the length thereof progressively, is adapted to be connected to the outer end of the plunger 3 by an adapter, indicated generally by the numeral 25, as hereinafter described.

As shown, the adapter 25 includes a pair of internally threaded tubular sockets, numbered 26 and 27, which are receivable on correspondingly threaded end portions of the plunger 3 and an adjoining section of the tubular metal conduit 24, respectively. The tubular socket 27 is interchangeable with other like tubular sockets for use with conduits of different sizes.

The tubular sockets 26 and 27 are closed at one end by a pair of tlat circular plates 28 having the same diameter, larger than the diameters of the tubular sockets 26 and 27, respectively, whereby marginal portions of the ilat circular plates 28 form radially outwardly extending peripheral anges. Y

The tubular socket 26 may be omitted, and the corresponding tlat circular plate 28 may be connected directly to the outer end of the plunger 3, as by welding, if desired.

The flat circular plates 28 are adapted to be removably connected in mutually opposed relation to each other by means of a split ring having semi-circular sections 29, channel shaped in transverse section, and having an annular groove in its inner peripheral surface normally embracing the radially outwardly extending anges comprising Amarginal portions of the opposed at circular plates 28.

The semi-circular sections 29 of the split ring connecting the at circular plates 28 are connected on one side by a hinge 30, and are adapted to be removably connected on the opposite side `by a hinged bolt 31 having a wing nut 32 applied thereto.

An internally threaded cap 33 advantageously may be applied to the `forward end of the tubular metal conduit 24, opposite the adapter 25. The cap 33 forms a spear head for use in penetrating the earth below a paved surface ahead of the tubular metal conduit 24, and is of larger diameter than the conduit 24 whereby it is adapted to form a passage suiciently large to accommodate the conduit 24 without binding.

Upon reciprocal movement of the plunger 3 relative to the cylinder 2 of the hydraulic ram 1, the tubular metal conduit 24 is adapted to be driven into the earth below a paved surface, on each forward stroke of the plunger 3, a distance corresponding to the length of the stroke, the pawl 17 being in its operative position and the carriage S and the cylinder 2 remaining stationary.

On each reverse stroke of the plunger 3 the cylinder 2 is advanced forwardly a distance corresponding to the length of the stroke, the plunger V3 being restrained against movement by frictional engagement of the earth surrounding the conduit 24 and the carriage 5 being brought forward with the cylinder 2.

The carriage advantageously may be advanced forwardly continuously, by steps, by the operation of the hydraulic ram 1, as above described, a distance corresponding substantially to the length of a single section of the tubular metal conduit 24. Thereafter the direction of movement of the carriage 5 may be reversed, the pawls 19 being in their operative positions, whereby the carriage 5 is returned to its original position, an additional section may be connected to the conduit 24, and the operation may be repeated.

The invention may be modied in various ways without departing from the spirit and scope thereof.

I claim:

In a tool for driving a sectional tubular metal conduit under a paved surface, such as an airport runway, to provide a duct below the pavement extending across it from one side to the other, the combination of an integral track unit adapted to be arranged in a trench extending laterally outwardly from the paved surface, perpendicular to the adjacent side thereof, having a pair of elongated rail elements, channel shaped in transverse section, arranged in parallel, spaced apart relation to each other with their side flanges opposed, and having a supporting structure including a plurality of uniformly spaced cross bars whereby the elongated rail elements are connected intermediate their ends, a carriage supported for longitudinal `movement relative to the track unit and having wheels engageable between the anges of the elongated rail elements, a hydraulic ram on the carriage having its cylinder arranged on its side, parallel to the track unit, and having its plunger extending outwardly beyond one end of the carriage, means for removably connecting an adjoining section of a tubular metal conduit to the outer end of the plunger, in axially aligned relation thereto, and pawls pivotally connected to opposite ends of the carriage for selective engagement, respectively, with the cross bars to prevent longitudinal movement of the carriage in one direction while permitting movement of the carriage in the opposite direction in response to the action of the hydraulic ram, the pawls being operable alternatively to thereby control the direction of movement of the carriage.

References Cited in the le of this patent UNITED STATES PATENTS 750,9'59 Free Feb. 2, 1904 1,117,150 Ammon Nov. 17, 1914 1,698,498 Harding Ian. 8, 1929 1,962,228 Abramson et al June 12, 1934 2,685,430 Henke Aug. 3, 1954 2,935,298 Wilwerding May 3, 1960 

